Coun Douly (Condulli) Rankin (ca 1774 – February 4, 1852) was a Scottish-born army officer and political figure in Prince Edward Island.
In 1804, Rankin was named a temporary lieutenant in the New Brunswick Fencibles; later that year, he married Flora Morison.
After being put on half pay, Rankin left the island in 1816 and settled on the Isle of Mull where he married Margaret Maclaine in 1818; his first wife had died in 1814.
He was named high sheriff for the island and so was responsible for collecting quitrents for Lieutenant Governor Charles Douglass Smith.
Rankin helped organize the tenants against the landowners; this eventually led to him being evicted from the farm that he had been renting and he moved to Charlottetown.